In a hard-rock mining operation, compressing the time required to bring an ore body into production allows for a faster generation of value, for an increase in the operating margins and to ensure that a project is completed on time and inside the boundaries of a predefined budget.
In this context, a new technology, named “RAIL-VEYOR”provides a new platform to revolutionize the way material is removed of an underground mine. The RAIL-VEYOR technology presents the opportunity to challenge the current historic low rate of development of underground mines of 35 meters per week.
The RAIL-VEYOR is a new type of particulate transportation machine, designed for general purposes, such as transporting minerals, cement and wood chips. The RAIL-VEYOR comprises a pair of rails, and a set of cars interconnected by clevis joints. Each one of these cars communicates with the adjacent car, revealing no boundaries between them. The element comprised by the cars, that allow this mutual connection, is an urethane flap, designed to cover the gap among two adjacent cars, providing a continuous surface at the bottom of the cars.
The RAIL-VEYOR cars do not comprehend any internal drive. They are moved along the rails by means of external drive stations which comprise rubber tires associated with electric motors. The external surface of those rubber tires are positioned in parallel with the side surfaces of the cars, and when those tires spin, they propel the Rail-Veyor forward, in the similar way that a roller coaster car is propelled over its track.
Another particular feature of this transportation method is the inclusion of an upper guiding plate inside of the rails, which prevents the cars from de-railing when they come across a vertical loop ahead in their path. This vertical loop defined by the RAIL-VEYOR's rails allows the cars to be turned upside-down, above a storage site, for the sake of material discharging.
Although the RAIL-VEYOR can be considered “breakthrough technology” which opens a new line of opportunity to speed up the ore extraction process, when the whole ore removal operation in a hard rock mining is taken into consideration, taking into account all the auxiliary machines and methods that operate in conjunction with the RAIL-VEYOR, this technology alone is not capable of diminishing the time for the ore removal execution.
Conventional methods of development do not use the RAIL-VEYOR technology in hard rock mining operations, and they involve other auxiliary equipment, procedures and methods that advance at slower rates, but have been utilized extensively in traditional development processes. For example, conventional methods of development have more extensive use of the LHD (load haul dump) equipment and haulage trucks. During the ore removal process, the LHD unit is empty (carrying no payload) 50% of the time. This equipment is very dependent on a human operator's skill and requires a great level of attention by the personnel involved in its manipulation. Further, it is noteworthy that the increased productivity levels demanded by the mining industry require that an operator performs the load-haul-dump cycle up to 250 times each working shift. This level of repetitive work cannot be safely sustained for the whole period as an operator will quickly tire after only four hours, thereby significantly increasing the risk of making costly mistakes that can result in equipped damage or even injury.
Other factors that contribute to slow down the ore removal operation in conventional operations, aside from the LHD units, are:
A large cross-section area of the ramp (currently in the range of at least 5 m high and 5 m wide) which require more holes to be drilled on the work face of the ramps for the placement of the explosive charges;
Interference of machines and personal that get across each other when traveling in opposite directions inside of the ramp; and
The slow installation of ground support due to a higher ground support surface area and the old-fashioned methods currently employed in this operation;
Objectives
It is proposed that the following objectives would be desirable in appropriate development applications:                To speed up the process of development of an access to the ore body inside a hard rock mine.        To remove the bottlenecks comprised by the conventional ramp development methods.        To provide more safety for the hard rock mining process.        